Peroxy compounds are effective bleaching agents, and compositions including mono- or diperoxyacid compounds are useful for industrial or home laundering operations. For example, U.S. Pat. No. 3,996,152, issued Dec. 7, 1976, inventors Edwards et al., discloses bleaching compositions including peroxygen compounds such as diperazelaic acid and diperisophthalic acid.
Peroxyacids (also known as "peracids) have typically been prepared by the reaction of carboxylic acids with hydrogen peroxide in the presence of sulfuric acid. For example, U.S. Pat. No. 4,337,213, inventors Marynowski et al., issued June 29, 1982, discloses a method for making diperoxyacids in which a high solids throughput may be achieved.
However, granular bleaching products containing peroxyacid compounds tend to lose bleaching activity during storage, due to decomposition of the peroxyacid. The relative instability of peroxyacid presents a problem of storage stability for compositions consisting of or including peroxyacids.
One approach to the problem of reduced bleaching activity of peroxyacid compositions has been to include "activators" for or precursors of peroxyacids. U.S. Pat. No. 4,283,301, inventor Diehl, issued Aug. 11, 1981, discloses bleaching compositions including peroxygen bleaching compounds, such as sodium perborate monohydrate or sodium perborate tetrahydrate, and activator compounds such as isopropenyl hexanoate and hexanoyl malonic acid diethyl ester. However, these bleach activators tend to yield an unpleasant odor under actual wash conditions. U.S. Pat. No. 4,486,327, inventors Murphy et al., issued Dec. 4, 1984, and U.S. Pat. No. 4,536,314, inventors Hardy et al., issued Aug. 20, 1985, disclose certain alpha substituted derivatives of C.sub.6 -C.sub.18 carboxylic acids which are said to activate peroxygen bleaches and are said to reduce malodor.
U.S. Pat. No. 4,539,130, inventors Thompson et al., issued Sept. 3, 1985 (and its related U.S. Pat. No. 4,483,778, inventors Thompson et al., issued Nov. 20, 1984) disclose chloro, methoxy or ethoxy substituted on the carbon adjacent to the acyl carbon atom. U.S. Pat. No. 3,130,165, inventor Brocklehurst, issued Apr. 21, 1964, also discloses an .alpha.-chlorinated peroxyacid, which is said to be highly reactive and unstable.
U.S. Pat. No. 4,681,952, inventors Hardy et al., issued July 21, 1987, discloses peracids and peracid precursors said to be of the general type RXAOOH and RXAL, wherein R is said to be a hydrocarbyl group, X is said to be a hetero-atom, A is said to be a carbonyl bridging group, and L is a leaving group, such as an oxybenzene sulfonate. C.sub.6 through C.sub.20 alkyl substituted aryl are said to be preferred as R, with C.sub.6 -C.sub.15 alkyl said to be especially preferred for oxidative stability.
Chung et al., U.S. Pat. No. 4,412,934, issued Nov. 1, 1983, discloses bleaching compositions containing a peroxygen bleaching compound and a bleach activator of the general formula ##STR4## wherein R is an alkyl group containing from about 5 to about 18 carbon atoms, and L is a leaving group, the conjugate acid of which has a pK.sub..alpha. in the range of about 6 to about 13.
Nakagawa et al., U.S. Pat. No. 3,960,743, issued June 1, 1976, discloses an activating agent represented by the formula ##STR5## wherein R stands for an alkyl group having 1 to 15 carbon atoms, a halogen- or hydroxyl-substituted alkyl group having 1 to 16 carbon atoms or a substituted aryl group, B designates a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, M represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkali metal, and n is an integer of at least 1 when M is an alkyl group or n is an integer of at least 2 when M is a hydrogen atom or an alkali metal. However, perhydrolysis of this activating agent substantially does not occur at the carbonyl adjacent the M substituent and the overall perhydrolysis that does occur tends to occur relatively slowly.
U.S. Pat. No. 4,778,618, Fong et al., issued Oct. 18, 1988 provides novel bleaching compositions comprising peracid precursors with the general structure ##STR6## wherein R is C.sub.1-20 linear or branched alkyl, alkylethoxylated, cycloalkyl, aryl, substituted aryl; R' and R"are independently H, C.sub.1-20 alkyl, aryl, C.sub.1-20 alkylaryl, substituted aryl, and NR.sub.3.sup..alpha.+, wherein R.sup..alpha. is C.sub.1-30 alkyl; and where L is a leaving group which can be displaced in a peroxygen bleaching solution by perhydroxide anion. The present invention is related to the Fong et al. glycolate ester peracid precursors in that precursors of the present invention are polyglycolates of the Fong et al. monoglycolate precursors. Further, compositions of the invention preferably include admixtures of the polyglycolate and glycolate precursors.